Article
Thermodynamics
Sai Kiran Hota, Kuan-Lin Lee, Brett Leitherer, George Elias, Greg Hoeschele, Srujan Rokkam
Summary: Two-phase-based heat spreaders are highly sought after for electronics cooling due to their superior thermal performance. Pulsating Heat Pipes (PHPs) offer thickness, shape, and cost advantages over Embedded Heat Pipe (EHP) spreaders. The thermal performance of PHP with different fluids was experimentally determined and compared to EHP. A mathematical model was developed and validated. Propylene-filled PHP performs similarly or better than EHP at low sink temperatures but dries out faster at moderate temperatures. PHP with R245fa and acetone improves with increasing power but has lower thermal conductivity compared to EHP. PHP is lighter than EHP based on weight comparison.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Chenxi Li, Ji Li
Summary: With the development of the data center industry, it has become crucial to remove waste heat from small-area heat sources for the safe and efficient operation of data processing chips. This study proposed a novel three-dimensional flat plate aluminum pulsating heat pipe (3D-FPPHP) with four different channel structures for radial heat dissipation of high-power server chips. The results showed that the FPPHP filled with acetone could start up easily and had good robustness during variable power operation.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Article
Energy & Fuels
Niti Kammuang-Lue, Chinphat Patanathabutr, Phrut Sakulchangsatjatai, Pradit Terdtoon
Summary: This research aimed to investigate the thermal characteristics of a rotating closed-loop pulsating heat pipe (RCLPHP) for integrating into rotating-type energy storage devices. The study observed the thermal characteristics from the start-up state to the post-critical state. It found that the RCLPHP exhibited temperature fluctuations in the evaporator and condenser sections during normal operation, and the internal phenomena of the working fluid resembled a slug-train. When the RCLPHP reached the critical state, the condenser section temperature subsequently decreased.
Article
Thermodynamics
Yang Gao, Zhiming Xu, Endi Zhai, Kunfeng Liang, Ran Zhao, Hailong Li, Lei Wang, Shengchun Liu, Xueqiang Li
Summary: In this study, a pulsating heat pipe (PHP) was designed and implemented to cool down the pitch cabinet in a wind turbine more effectively. Performance tests were conducted to compare the cooling performance with an air-based cooling system. The results showed that the PHP operated steadily under rotating conditions and successfully reduced temperature, making it more suitable than the air-based cooling system under varied conditions.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Florian Schwarz, Pascal Messmer, Alexander Lodermeyer, Vladimir Danov, Christian Flessner, Stefan Becker, Rolf Hellinger
Summary: This study compares different designs of pulsating heat pipes (PHPs), including flower-shaped and star-shaped designs, with the existing meander-shaped design. The results show that the flower-shaped design reduces thermal resistance and phase change plays a key role in thermal resistance. The study provides design criteria to optimize the thermal performance of PHPs.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Engineering, Manufacturing
Ze Wu, Hang Bao, Youqiang Xing, Lei Liu
Summary: By designing a pulsating heat pipe self-cooling tool holder, the cutting temperature can be effectively reduced, wear can be reduced, and tool life can be extended. The experimental results prove the successful application of this new structure.
JOURNAL OF MANUFACTURING PROCESSES
(2022)
Article
Automation & Control Systems
Ze Wu, Hang Bao, Youqiang Xing, Lei Liu
Summary: The heat transfer performance of open pulsating heat pipe (PHP) was experimentally investigated and a prediction model based on experimental data and boosting integrating learning methods was proposed. The model can be used to select the most suitable open PHP.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Thermodynamics
Kalpak R. Sagar, H. B. Naik, Hemantkumar B. Mehta
Summary: Numerical simulation of a 2-D Cryogenic Pulsating Heat Pipe using liquid nitrogen as working fluid was conducted. The study analyzed the volume fraction of liquid nitrogen under different operational conditions and performed qualitative and quantitative analysis of temperature, adiabatic wall temperature, and flow circulation velocity. Thermal oscillations with dominant frequency in a specific range were observed and analyzed using PSD and ACF tools.
INTERNATIONAL JOURNAL OF REFRIGERATION
(2021)
Review
Energy & Fuels
Chenxi Li, Ji Li
Summary: Pulsating heat pipe, as a branch of heat pipes, is a widely recognized passive cooling technique with advantages of small size, simple and compact structure, and high heat dissipation efficiency. Its application in data centers is still in the early stages with limited research and implementation reports available.
FRONTIERS IN ENERGY RESEARCH
(2021)
Article
Thermodynamics
Yun-Zhi Ling, Xiao-Hui She, Xiao-Song Zhang, Ting-Ting Chen, Xin-Ru Lin, Jun-Kai Feng
Summary: The current trend of miniaturisation and design flexibility poses challenges to thermal management systems. This study focused on a PCM-based thermal management system combined with a 3D-PHP and investigated its performance. The results showed that a 3D-PHP charged with methanol at a filling ratio of 34% exhibited the highest cooling efficiency.
APPLIED THERMAL ENGINEERING
(2022)
Article
Mechanics
Gampala Durga Priyadarsini, Gurunath Sankad
Summary: This research focuses on addressing a critical issue in modern microelectronics by studying pulsatile heat pipes and microfluidics. The study demonstrates the accuracy and efficiency of the heat transfer solution and highlights the advantages of pulsatile flows in microfluidic systems, providing promising avenues for future research.
Article
Thermodynamics
Alok Kumar, Suneet Singh
Summary: Heat pipes are used for high-heat transfer in electronic devices. The operation of Pulsating Heat Pipe is not fully understood due to the complexities involved. A phenomenological model has been developed to explain the thermodynamic processes, and the oscillatory behavior of the liquid slug is modeled. The onset of chaotic regimes in the heat transfer has not been addressed in previous works.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Thermodynamics
Ning Qian, Fan Jiang, Marco Marengo, Yucan Fu, Jiuhua Xu
Summary: Grinding of difficult-to-machining materials generates excessive heat. Radial-rotating oscillating heat pipe (RR-OHP) can enhance heat transfer and control the temperature during grinding. Experimental results demonstrate that RR-OHP improves heat transfer efficiency in grinding process significantly.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Jiajia Chen, Yucan Fu, Ning Qian, Huafei Jiang, Chan Y. Ching, Dan Ewing, Chenwei Dai
Summary: A new cooling method incorporating an axially rotating heat pipe (RHP) has been proposed for profile grinding, demonstrating great cooling advantages compared to traditional methods. The study analyzed the cooling behavior through simulation and experimental grinding of titanium alloys, providing insights for green machining in industrial products with complex profiles.
APPLIED THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Hongwu Deng, Zishuo Wang, Jiasen Wang, Hua Li
Summary: This study focuses on the rotational effects in an impingement cooling channel with film extraction, showing that channel rotation increases heat transfer in the low radius region on the pressure side. The non-uniform mass flow rate distribution leads to deterioration of heat transfer.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Mahsa Taghavi, Swapnil Sharma, Vemuri Balakotaiah
Summary: This study investigates the natural convection effects in the insulation layers of spherical storage tanks and their impact on the tanks' performance. The permeability and Rayleigh number of the insulation material are considered as key factors. The results show that as the Rayleigh number increases, new convective cells emerge and cause the cold boundary to approach the external hot boundary. In the case of large temperature differences, multiple solutions may coexist.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinyang Xu, Fangjun Hong, Chaoyang Zhang
Summary: This study introduces a self-induced jet impingement device for enhancing pool boiling performance in high power electronic cooling. Through visualization and parametric investigations, the effects of this device on pool boiling performance are studied, revealing the promotion of additional liquid supply and vapor exhausting. The flow rate of the liquid jet is found to positively impact boiling performance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Wenchao Ke, Yuan Liu, Fissha Biruke Teshome, Zhi Zeng
Summary: Underwater wet laser welding (UWLW) is a promising and labor-saving repair technique. A thermal multi-phase flow model was developed to study the heat transfer, fluid dynamics, and phase transitions during UWLW. The results show that UWLW creates a water keyhole, making the welding environment similar to in air laser welding.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Xingrong Lian, Lin Tian, Zengyao Li, Xinpeng Zhao
Summary: This study investigates the heat transfer mechanisms in natural fiber-derived porous structures and finds that thermal radiation has a significant impact on the thermal conductivity in low-density regions, while natural convection rarely occurs. Insulation materials derived from micron-sized natural fibers can achieve minimum thermal conductivity at specific densities. Strategies to lower the thermal conductivity include increasing porosity and incorporating nanoscale pores using nanosize fibers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Yasir A. Malik, Kilian Koebschall, Stephan Bansmer, Cameron Tropea, Jeanette Hussong, Philippe Villedieu
Summary: Ice crystal icing is a significant hazard in aviation, and accurate modeling of sticking efficiency is essential. In this study, icing wind tunnel experiments were conducted to quantify the volumetric liquid water fraction, sticking efficiency, and maximum thickness of ice layers. Two measurement techniques, calorimetry and capacitive measurements, were used to measure the liquid water content and distribution in the ice layers. The experiments showed that increasing wet bulb temperatures and substrate heat flux significantly increased sticking efficiency and maximum ice layer thickness.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinqi Hu, Tongtong Geng, Kun Wang, Yuanhong Fan, Chunhua Min, Hsien Chin Su
Summary: This study experimentally examined the heat dissipation of vibrating fans and demonstrated its inherent mechanism through numerical simulation. The results showed that the flow fields induced by the vibrating blades exhibited pulsating features and formed large-scale and small-scale vortical structures, significantly improving heat dissipation. The study also identified the impacts of different blade structures and developed a trapezoidal-folding blade, which effectively reduced the maximum temperature of the heat source and alleviated high-temperature failure crisis.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Dan-Dan Su, Xiao-Bin Li, Hong-Na Zhang, Feng-Chen Li
Summary: The boiling heat transfer of low-boiling-point working fluid is a common heat dissipation technology in electronic equipment cooling. This study analyzed the interfacial boiling behavior of R134a under different conditions and found that factors such as the initial thickness of the liquid film, solid-liquid interaction force, and initial temperature significantly affect the boiling mode and thermal resistance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinyi Wu, Dongke Sun, Wei Chen, Zhenhua Chai
Summary: A unified lattice Boltzmann-phase field scheme is proposed to simulate dendrite growth of binary alloys in the presence of melt convection. The effects of various factors on the growth are investigated numerically, and the model is validated through comparisons and examinations.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shaokun Ge, Ya Ni, Fubao Zhou, Wangzhaonan Shen, Jia Li, Fengqi Guo, Bobo Shi
Summary: This study investigated the temperature distribution of main cables in a suspension bridge during fire scenarios and proposed a prediction model for the maximum temperature of cables in different lane fires. The results showed that vehicle fires in the emergency lane posed a greater thermal threat to the cables.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shuang-Ying Wu, Shi-Yao Zhou, Lan Xiao, Jia Luo
Summary: This paper investigates the two-phase flow and heat transfer characteristics of low-velocity jet impacting on a cylindrical surface. The study reveals that the heat transfer regimes are non-phase transition and nucleate boiling with the increase of heat transfer rate. The effects of jet impact height and outlet velocity on local surface temperatures are pronounced at the non-phase transition stage. The growth rates of heat transfer rate and liquid loss rate increase significantly from the non-phase transition to nucleate boiling stage.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Emad Hasani Malekshah, Wlodzimierz Wlodzimierz, Miros law Majkut
Summary: Cavitation has significant practical importance and can be controlled by air injection. This study investigates the natural to ventilated cavitation process around a hydrofoil through numerical and experimental methods. The results show that the location and rate of air injection have a meaningful impact on the characteristics of cavitation.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Feriel Yahiat, Pascale Bouvier, Antoine Beauvillier, Serge Russeil, Christophe Andre, Daniel Bougeard
Summary: This study explores the enhancement of mixing performance in laminar flow equipment by investigating the generation of chaotic advection using wall deformations in annular geometries. The findings demonstrate that the combined geometry can achieve perfect mixing at various Reynolds numbers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Hui He, Ning Lyu, Caihua Liang, Feng Wang, Xiaosong Zhang
Summary: This study investigates the condensation, frosting, and defrosting processes on superhydrophobic surfaces with millimeter-scale structures. The results reveal that the structures can influence the growth and removal of frost crystals, with the bottom grooves creating a frost-free zone and conical edges promoting higher frost crystal heights. Two effective methods for defrosting are observed: hand-lifting the groove and airfoil retraction contraction on protruding structures. This research provides valuable insights into frost formation and defrosting on millimeter-structured superhydrophobic surfaces, with potential applications in anti-frost engineering.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Thiwanka Arepolage, Christophe Verdy, Thibaut Sylvestre, Aymeric Leray, Sebastien Euphrasie
Summary: This study developed two thermal concentrators, one with a 2D design of uniform thickness and another with a 3D design, using the coordinate transformation technique and metamaterials. By structuring the thermal conductor, the desired local density-heat capacity product and anisotropic thermal conductivities were achieved. The homogenized thermal conductivities were obtained from finite element simulations and cylindrical symmetry consideration. A 3D concentrator was fabricated using 3D metal printing and characterized using a thermal camera. Compared to devices that solely consider anisotropic conductivities, the time evolution characteristics of the metadevice designed with coordinate transformation were closer to those of an ideal concentrator.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Liangyuan Cheng, Qingyang Wang, Jinliang Xu
Summary: In this study, we investigated the supercritical heat transfer of CO2 in a horizontal tube with a diameter of 10.0 mm, covering a wide range of pressures, mass fluxes, and heat fluxes. The study revealed a non-monotonic increase in wall temperatures along the flow direction and observed both positive and negative wall temperature differences between the bottom and top tube. The findings were explained by the thermal conduction in the solid wall interacting with the stratified-wavy flow in the tube.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)